It is against the Apple license to distribute even derivatives of the iPhone headers so you must build them manually from the Objective-C headers using the parser.

Please note you must download the iPhone SDK (2GB+) from Apple's website (https://developer.apple.com/iphone), which contains the headers. Once the files are installed make sure the following SDK is available at this location:

/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS3.2.sdk/System/Library/Frameworks/UIKit.framework/Headers

To build the iOS Objective-Pascal headers (only supported for the iOS 3.2 SDK headers at this time, other SDK versinos will probably result in errors and require manual modification),
1) cd to the directory which contains parser.php (the current directory)
2) ./make-ios-headers.sh

The built headers will be placed under uikit-skel/src.